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Testing the claim: "I can hear differences between lossless formats."

Discussion in 'Sound Science' started by music alchemist, Oct 15, 2014.
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  1. Music Alchemist
    @KlarkKentThe3rd and others who claim to hear differences between lossless formats (WAV, AIFF, FLAC, ALAC, etc.)...or even 24-bit vs 16-bit...
     
    I created this thread for you to present your case and test it scientifically.
     
    If those among you who know how to conduct proper tests would be so kind as to assist in any manner you see fit, it would be appreciated.
     
    I ask that everyone approach this experiment with respect and avoid taking anything personally.
     
  2. bigshot
    The simplest way is to simply take the various file types and put them all into a WAV file. Then blind compare them. The problem that I've found with this is that if the cat's away, the mice will play. I did a test like this with lossy and a "golden ear" deliberately cheated by opening up the files and comparing the waveforms. The only way to be absolutely sure with that test is to do the test in person double blind.
     
  3. cjl
    If they're all lossless, the waveforms will be bit-for-bit identical. You can't cheat that way. Of course, if the claim is that the lossless files sound different when played back from the various lossless formats, you could simply cheat by looking at the file extensions. If the degradation is supposedly persistent though, you could convert a .wav into the various lossless formats, convert them back to .wav, and then (assuming no level changing during the encoding or anything like that), there would be no way to cheat. The encoding is perfect.
     
  4. Music Alchemist
    Let's wait for @KlarkKentThe3rd to tell his story here, then we can have him properly test them.
     
    (He's the one making the claims, not me. [​IMG])
     
  5. bigshot
     
    If he is claiming the problem he hears is with the lossless codec itself, then making everything a WAV file and asking him to tell the difference would be a fine test.
     
    If he is claiming his playback equipment plays back lossless files with different sound, then he should get better equipment.
     
  6. castleofargh Contributor
    I guess if you really have a crappy power supply not giving at all enough power to the computer, (like having 5 10000turn/s hard drives and 3 top class gfx cards and you power your Xmas lights with USB on a 250W power supply with a pentium2 processor always at 100% from pr0n viruses. then maybe you could find situations where having to extract the flac could make a difference? maybe?
     
    another thing that would come to mind is a very high noise coming from the computer and bleeding into the music signal. then when processing more to extract the flac it could make more noise?
     
    third would be a software problem, the media player being buggy with some codecs???? I know it existed on some DAPs, but is that really a thing on computer? 
     
     
    in all 3 situations, it would be a very strong indication of crappy computer/installation, not of lossless differences.
     
    I really can't think of another reason that wouldn't be placebo or nooby encoding.
     
  7. Music Alchemist
    Since he hasn't joined in yet, I will quote what he said in other threads so far:
     
     
    Since he claims to be able to easily hear a difference, testing that claim through proper experimentation should be no problem.
     
    We just need to wait for him to reply here. I sent him a PM, so hopefully, he'll show up.
     
  8. KlarkKentThe3rd
    Well this is flattering. Someone makes a thread "for you", and so you are given this sense of obligation to post in it. Thanks for the extra guilt, man!
     
    Anyways, I discovered the difference between formats when I was editing tracks from Spyro the Dragon videogames (the first 3). I extracted them as WAV (the default and only format of the extracting software), edited them in Audacity (fixed the fade outs, added/removed silence), and exported in AIFF (to later convert to ALAC).
     
    Now, when I edit, I listen to the entire track in Audacity at least once, and numerous times to the beginning and final 10 seconds. After hearing it about 20 times, and then listening to the AIFF copy in iTunes, I began to notice that the AIFF always sounds worse somehow. I tried waiting and using the newer version of Audacity, but it didn't help. I thought that converting between lossless formats damages/alters the date somehow, and tried exporting as WAV instead. THE SOUND OF THE EXPORT WAS PERFECT ON THE VERY FIRST TRY. Out of curiosity, I tried converting something that was not WAV, into WAV. The sound got "warmer" and more "realistic" instantly.
     
    So, this is the conclusion I came to after exporting WAV as AIFF for about 200 times:
     
    AIFF sounds colder and less realistic, while WAV sounds warm and natural. Converting an AIFF file to WAV makes it sound better, therefore no information is damaged during conversion, it is something in the codec... or something.
     
     
    You may point to the fact I was dealing with old videogame soundtracks, and they don't sound realistic. Don't worry, I converted many acoustic and orchestral tracks as well, and the result was the same EVERY SINGLE TIME.
     
    ALAC sounds slightly better than AIFF, but still relatively cold, while FLAC sounds a bit compressed (as if it was lossy) when you use any compression level other than 0.
     
     
     
    Conclusion: WAV and FLAC 0 are PERFECT. AIFF and ALAC are NOT.
     
  9. castleofargh Contributor
    -I know placebo
    -show me!
    tumblr_li5dltojBy1qhbvkso1_500.jpg
     
     
    as yoda said: Only a fully trained Jedi Knight, with the force as his ally, will conquer bias and placebo.
     
    maibuN likes this.
  10. money4me247 Contributor
     
    If you convert a "perfect" lossless format into a "non-perfect" lossless format that results in degradation of sound quality... when you re-convert it back into the "perfect" lossless format, the degradation of sound quality from the conversion should be reproduced perfectly. therefore, if aiff sounds colder & less realistic to you, a file that has been converted into aiff back into wav/flac should also sound colder & less realistic. since that is not the case, this is strongly suggestive of placebo effect/expectation bias & you may not have a good understanding of the digital audio conversion process.
     
    I am guessing that the reason a thread made for you if because your claims are so counter to how science understands digital conversion to work that some people want you to try a blind test to show you that you are most likely mistaken.
     
    edit1: here is some useful information for you to read:
    http://lifehacker.com/5927052/whats-the-difference-between-all-these-audio-formats-and-which-one-should-i-use
    http://www.howtogeek.com/howto/40465/htg-explains-what-are-the-differences-between-all-those-audio-formats/
    http://www.pooraudiophile.com/2013/07/difference-between-flac-vs-alac-recordings.html
     
    Vkamicht likes this.
  11. Strangelove424
    AIFF is PCM.... WAV is PCM.... They are both uncompressed lossless. It's the same exact bit info. To think you can hear a difference between two PCM versions of a song is absolutely ludicrous. You might as well think you hear differences between two copies of the same CD. 
     
    Vkamicht likes this.
  12. Music Alchemist
     
    Actually, he is saying that his software (iTunes and Audacity) processes the data in different ("not perfect") ways during playback, resulting in an allegedly different sound. Everyone here is in agreement that lossless files can be converted to other lossless formats with no loss in data.
     
    The next phase is proper testing. As I requested, if anyone can provide step-by-step instructions for him, it will be helpful.
     
  13. money4me247 Contributor
    my apologies. i misinterpreted his claim.
     
    in regards to differences in playback of different lossless files unrelated to compression, I would imagine this is highly unlikely.
     
    However, I googled it for you & there this a claim (opposite of yours) that ALE sounds worse than AIFF if "sound check" is enabled on itunes. the only other thing I can think of is that alc lacks error handling to detect corruption during conversion, but if that was the issue, then as I stated earlier, the issue will still be present upon reconversion into another lossless format.
     
  14. Music Alchemist
     
    Please remember that I'm not the one making any claims here. My role is to merely be a neutral party to facilitate the tests I am proposing.
     
  15. money4me247 Contributor
    hahaha, yea, i meant you towards the supermandude.
     
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